The show's official website released a motion comic based on the first issue of the original comic and voiced by Phil LaMarr. The site also posted a making-of documentary primarily about the first episode, as well as a number of other behind-the-scenes videos and interviews. In the documentary, comic series creator and show executive producer Robert Kirkman as well as artist Charlie Adlard expressed that they were pleased with how faithful the show is to the comic and remark on the similarities between the actors and the comic's original character drawings. Several scenes from "Days Gone Bye" were screened July 23, 2010 as part of the 2010 San Diego Comic-Con International. Hurd asserted that "[they] really are doing six one-hour movie", and Darabont insisted that the series would closely reflect the development in the comics. "The path is a very strong template. But we're going to take every interesting detour we feel like taking. As long as were staying on the path of what Robert has done, I don't see any reason not to. If they have patience we'll eventually catch up to what Robert is doing."
The Walking Dead debuted during the same week in 120 countries. "Days Gone Bye" premiered in Hong Kong on TVB Pearl on August 30, 2011, while it expanded in international markets during the first week of November. Two weeks prior to its official premiere in the United States, the contents of the episode leaked online. As part of an expansive campaign to advertise and heighten anticipation for the premiere, international broadcasting affiliates of AMC and Fox coordinated a worldwide zombie invasion event proceeding days prior to premiere of the episode in the United States. The event occurred in twenty six cities worldwide,and were hosted in select locations including the Brooklyn Bridge in New York City, Lincoln Memorial in Washington, D.C., Palace of Westminster in London, Bosphorus Bridge in Istanbul, Acropolis of Athens in Athens, and the Museo del Prado in Madrid. The campaign events commenced in Hong Kong and Taipei, and culminated in Los Angeles.
The Walking Dead was included on the cover of the December 2010 edition of Entertainment Weekly, which featured Rick Grimes pointing a gun at a horde of walkers. According to the journalist of the magazine, it "examines the past, present, and future" of the television franchise; "from the comic book’s humble beginnings, to unlikely path to the small screen, to even more unlikely path as a bona fide hit." Kirkman was ecstatic upon hearing of the news. "I've got to say—not to kiss your magazine's a– or anything—but when they called me and said Frank [Darabont] wanted to do the show, I was like, 'Yeah, I'll believe it when I see it.' And then when AMC was like, 'We're picking up the show,' I was like, 'Yeah, alright, whatever.' When they actually started shooting the pilot I was like, 'Well, this is kind of real, this is neat.' But when they called me and said, 'Your show’s on the cover of Entertainment Weekly,' I think that was the first time I was like, 'Oh my god, I can’t believe this is happening to me!'"
Source : http://en.wikipedia.org/wiki/The_Walking_Dead_%28season_1%29